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      <a id="moogladder"></a>
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        <h2>
          <span class="refentrytitle">moogladder</span>
        </h2>
        <p>moogladder — 
      Moog ladder lowpass filter.
    </p>
      </div>
      <div class="refsect1">
        <a id="idp126299840"></a>
        <h2>Description</h2>
        <p>
Moogladder is an new digital implementation of the Moog ladder filter based on 
the work of Antti Huovilainen, described in the paper "Non-Linear Digital 
Implementation of the Moog Ladder Filter" (Proceedings of DaFX04, Univ of Napoli). 
This implementation is probably a more accurate digital representation of 
the original analogue filter. 
    </p>
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      <div class="refsect1">
        <a id="idp126301392"></a>
        <h2>Syntax</h2>
        <pre class="synopsis">asig <span class="command"><strong>moogladder</strong></span> ain, kcf, kres[, istor]</pre>
        <pre class="synopsis">asig <span class="command"><strong>moogladder</strong></span> ain, acf, kres[, istor]</pre>
        <pre class="synopsis">asig <span class="command"><strong>moogladder</strong></span> ain, kcf, ares[, istor]</pre>
        <pre class="synopsis">asig <span class="command"><strong>moogladder</strong></span> ain, acf, ares[, istor]</pre>
      </div>
      <div class="refsect1">
        <a id="idp126376016"></a>
        <h2>Initialization</h2>
        <p>
      <span class="emphasis"><em>istor</em></span> --initial disposition of internal
      data space. Since filtering incorporates a feedback loop of
      previous output, the initial status of the storage space used is
      significant.  A zero value will clear the space; a non-zero
      value will allow previous information to remain. The default
      value is 0.
    </p>
      </div>
      <div class="refsect1">
        <a id="idp126377952"></a>
        <h2>Performance</h2>
        <p>
      <span class="emphasis"><em>asig</em></span> -- input signal.
    </p>
        <p>
      <span class="emphasis"><em>kcf</em></span>/<span class="emphasis"><em>acf</em></span> -- filter cutoff frequency
    </p>
        <p>
      <span class="emphasis"><em>kres</em></span>/<span class="emphasis"><em>ares</em></span> --
      resonance, generally &lt; 1, but not limited to it.  Higher than
      1 resonance values might cause aliasing, analogue synths
      generally allow resonances to be above 1. 
    </p>
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      <div class="refsect1">
        <a id="idp126382464"></a>
        <h2>Examples</h2>
        <p>
      Here is an example of the moogladder opcode. It uses the file <a class="ulink" href="examples/moogladder.csd" target="_top"><em class="citetitle">moogladder.csd</em></a>.
      </p>
        <div class="example">
          <a id="idp126384240"></a>
          <p class="title">
            <strong>Example 525. Example of the moogladder opcode.</strong>
          </p>
          <div class="example-contents">
            <p>See the sections <a class="link" href="UsingRealTime.html" title="Real-Time Audio"><em class="citetitle">Real-time Audio</em></a> and <a class="link" href="CommandFlags.html" title="Csound command line"><em class="citetitle">Command Line Flags</em></a> for more information on using command line flags.</p>
            <pre class="programlisting">
<span class="csdtag">&lt;CsoundSynthesizer&gt;</span>
<span class="csdtag">&lt;CsOptions&gt;</span>
<span class="comment">; Select audio/midi flags here according to platform</span>
-odac   <span class="comment">;;;realtime audio out</span>
<span class="comment">;-iadc    ;;;uncomment -iadc if realtime audio input is needed too</span>
<span class="comment">; For Non-realtime ouput leave only the line below:</span>
<span class="comment">; -o moogladder.wav -W ;;; for file output any platform</span>
<span class="csdtag">&lt;/CsOptions&gt;</span>
<span class="csdtag">&lt;CsInstruments&gt;</span>

<span class="ohdr">sr</span> <span class="op">=</span> 44100
<span class="ohdr">ksmps</span> <span class="op">=</span> 32
<span class="ohdr">nchnls</span> <span class="op">=</span> 2
<span class="ohdr">0dbfs</span>  <span class="op">=</span> 1

<span class="oblock">instr</span> 1

kfe  <span class="opc">expseg</span> 500, p3<span class="op">*</span>0.9, 1800, p3<span class="op">*</span>0.1, 3000
asig <span class="opc">buzz</span>  1, 100, 20, 1
kres <span class="opc">line</span> .1, p3, .99	<span class="comment">;increase resonance</span>
afil <span class="opc">moogladder</span> asig, kfe, kres
     <span class="opc">outs</span> afil, afil

<span class="oblock">endin</span>
<span class="csdtag">&lt;/CsInstruments&gt;</span>
<span class="csdtag">&lt;CsScore&gt;</span>
<span class="stamnt">f</span> 1 0 4096 10 1

<span class="stamnt">i</span> 1 0 10
<span class="stamnt">e</span>
<span class="csdtag">&lt;/CsScore&gt;</span>
<span class="csdtag">&lt;/CsoundSynthesizer&gt;</span>
</pre>
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        <p><br class="example-break" />
    </p>
      </div>
      <div class="refsect1">
        <a id="idp126388528"></a>
        <h2>Credits</h2>
        <p>
      </p>
        <table border="0" summary="Simple list" class="simplelist">
          <tr>
            <td>Author: Victor Lazzarini</td>
          </tr>
          <tr>
            <td>January 2005</td>
          </tr>
        </table>
        <p>
    </p>
        <p>New plugin in version 5</p>
        <p>January 2005.</p>
        <p>Audio rate parameters introduced in version 6.02</p>
        <p>October 2013.</p>
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